3.0 rounded to the nearest 10

The local farm is advertising a special on fresh picked peaches. the farm charges $4.25 to pick your own peck of peaches and $3.50 for each additional peck you pick. write an equation for the total cost of peaches in terms of the number of pecks. deine your variables. how much does it cost to pick 3 pecks of peaches?

Ineed if you could explain and give me the answer you! this needs done

Consider the function represented by the equation 1/2 j + 1/4 k equals 3 which shows the equation written in function notation with j as the independent variable